Fyath, R. S., and M. T. Rashid. “Performance of Double - Frequency Parameter Shift Keying (DFPSK) System in the Presence of Dichroism”. Iraqi Journal for Electrical and Electronic Engineering, vol. 1, no. 1, Jan. 2002, pp. 107-21, https://doi.org/10.37917/ijeee.1.1.8.